We present measurements of the weak gravitational lensing shear power spectrum based on \(450\) sq. deg. of imaging data from the Kilo Degree Survey. We employ a quadratic estimator in two and three ...redshift bins and extract band powers of redshift auto-correlation and cross-correlation spectra in the multipole range \(76 \leq \ell \leq 1310\). The cosmological interpretation of the measured shear power spectra is performed in a Bayesian framework assuming a \(\Lambda\)CDM model with spatially flat geometry, while accounting for small residual uncertainties in the shear calibration and redshift distributions as well as marginalising over intrinsic alignments, baryon feedback and an excess-noise power model. Moreover, massive neutrinos are included in the modelling. The cosmological main result is expressed in terms of the parameter combination \(S_8 \equiv \sigma_8 \sqrt{\Omega_{\rm m}/0.3}\) yielding \(S_8 = \ 0.651 \pm 0.058\) (3 z-bins), confirming the recently reported tension in this parameter with constraints from Planck at \(3.2\sigma\) (3 z-bins). We cross-check the results of the 3 z-bin analysis with the weaker constraints from the 2 z-bin analysis and find them to be consistent. The high-level data products of this analysis, such as the band power measurements, covariance matrices, redshift distributions, and likelihood evaluation chains are available at http://kids.strw.leidenuniv.nl/
In this paper we present results of applying the shear-ratio method to the RCSLenS data. The method takes the ratio of the mean of the weak lensing tangential shear signal about galaxy clusters, ...averaged over all clusters of the same redshift, in multiple background redshift bins. In taking a ratio the mass-dependency of the shear signal is cancelled-out leaving a statistic that is dependent on the geometric part of the lensing kernel only. We apply this method to 535 clusters and measure a cosmology-independent distance-redshift relation to redshifts z~1. In combination with Planck data the method lifts the degeneracies in the CMB measurements, resulting in cosmological parameter constraints of OmegaM=0.31 +/- 0.10 and w0 = -1.02 +/- 0.37, for a flat wCDM cosmology.
We present cosmological parameter constraints from a tomographic weak gravitational lensing analysis of ~450deg\(^2\) of imaging data from the Kilo Degree Survey (KiDS). For a flat \(\Lambda\)CDM ...cosmology with a prior on \(H_0\) that encompasses the most recent direct measurements, we find \(S_8\equiv\sigma_8\sqrt{\Omega_{\rm m}/0.3}=0.745\pm0.039\). This result is in good agreement with other low redshift probes of large scale structure, including recent cosmic shear results, along with pre-Planck cosmic microwave background constraints. A \(2.3\)-\(\sigma\) tension in \(S_8\) and `substantial discordance' in the full parameter space is found with respect to the Planck 2015 results. We use shear measurements for nearly 15 million galaxies, determined with a new improved `self-calibrating' version of \(lens\)fit validated using an extensive suite of image simulations. Four-band \(ugri\) photometric redshifts are calibrated directly with deep spectroscopic surveys. The redshift calibration is confirmed using two independent techniques based on angular cross-correlations and the properties of the photometric redshift probability distributions. Our covariance matrix is determined using an analytical approach, verified numerically with large mock galaxy catalogues. We account for uncertainties in the modelling of intrinsic galaxy alignments and the impact of baryon feedback on the shape of the non-linear matter power spectrum, in addition to the small residual uncertainties in the shear and redshift calibration. The cosmology analysis was performed blind. Our high-level data products, including shear correlation functions, covariance matrices, redshift distributions, and Monte Carlo Markov Chains are available at http://kids.strw.leidenuniv.nl.
We present weak lensing and X-ray analysis of 12 low mass clusters from the CFHTLenS and XMM-CFHTLS surveys. We combine these systems with high-mass systems from CCCP and low-mass systems from COSMOS ...to obtain a sample of 70 systems, spanning over two orders of magnitude in mass. We measure core-excised Lx-Tx, M-Lx and M-Tx scaling relations and include corrections for observational biases. By providing fully bias corrected relations, we give the current limitations for Lx and Tx as cluster mass proxies. We demonstrate that Tx benefits from a significantly lower intrinsic scatter at fixed mass than Lx. By studying the residuals of the bias corrected relations, we show for the first time using weak lensing masses that galaxy groups seem more luminous and warmer for their mass than clusters. This implies a steepening of the M-Lx and M-Tx relations at low masses. We verify the inferred steepening using a different high mass sample from the literature and show that variance between samples is the dominant effect leading to discrepant scaling relations. We divide our sample into subsamples of merging and relaxed systems, and find that mergers may have enhanced scatter in lensing measurements, most likely due to stronger triaxiality and more substructure. For the Lx-Tx relation, which is unaffected by lensing measurements, we find the opposite trend in scatter. We also explore the effects of X-ray cross-calibration and find that Chandra calibration leads to flatter Lx-Tx and M-Tx relations than XMM-Newton.
We present new constraints on the relationship between galaxies and their host dark matter halos, measured from the location of the peak of the stellar-to-halo mass ratio (SHMR), up to the most ...massive galaxy clusters at redshift \(z\sim0.8\) and over a volume of nearly 0.1~Gpc\(^3\). We use a unique combination of deep observations in the CFHTLenS/VIPERS field from the near-UV to the near-IR, supplemented by \(\sim60\,000\) secure spectroscopic redshifts, analysing galaxy clustering, galaxy-galaxy lensing and the stellar mass function. We interpret our measurements within the halo occupation distribution (HOD) framework, separating the contributions from central and satellite galaxies. We find that the SHMR for the central galaxies peaks at \(M_{\rm h, peak} = 1.9^{+0.2}_{-0.1}\times10^{12} M_{\odot}\) with an amplitude of \(0.025\), which decreases to \(\sim0.001\) for massive halos (\(M_{\rm h} > 10^{14} M_{\odot}\)). Compared to central galaxies only, the total SHMR (including satellites) is boosted by a factor 10 in the high-mass regime (cluster-size halos), a result consistent with cluster analyses from the literature based on fully independent methods. After properly accounting for differences in modelling, we have compared our results with a large number of results from the literature up to \(z=1\): we find good general agreement, independently of the method used, within the typical stellar-mass systematic errors at low to intermediate mass (\({M}_{\star} < 10^{11} M_{\odot}\)) and the statistical errors above. We have also compared our SHMR results to semi-analytic simulations and found that the SHMR is tilted compared to our measurements in such a way that they over- (under-) predict star formation efficiency in central (satellite) galaxies.
The Kilo-Degree Survey (KiDS) is an optical wide-field survey designed to map the matter distribution in the Universe using weak gravitational lensing. In this paper, we use these data to measure the ...density profiles and masses of a sample of \(\sim \mathrm{1400}\) spectroscopically identified galaxy groups and clusters from the Galaxy And Mass Assembly (GAMA) survey. We detect a highly significant signal (signal-to-noise-ratio \(\sim\) 120), allowing us to study the properties of dark matter haloes over one and a half order of magnitude in mass, from \(M \sim 10^{13}-10^{14.5} h^{-1}\mathrm{M_{\odot}}\). We interpret the results for various subsamples of groups using a halo model framework which accounts for the mis-centring of the Brightest Cluster Galaxy (used as the tracer of the group centre) with respect to the centre of the group's dark matter halo. We find that the density profiles of the haloes are well described by an NFW profile with concentrations that agree with predictions from numerical simulations. In addition, we constrain scaling relations between the mass and a number of observable group properties. We find that the mass scales with the total r-band luminosity as a power-law with slope \(1.16 \pm 0.13\) (1-sigma) and with the group velocity dispersion as a power-law with slope \(1.89 \pm 0.27\) (1-sigma). Finally, we demonstrate the potential of weak lensing studies of groups to discriminate between models of baryonic feedback at group scales by comparing our results with the predictions from the Cosmo-OverWhelmingly Large Simulations (Cosmo-OWLS) project, ruling out models without AGN feedback.
We present data products from the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). CFHTLenS is based on the Wide component of the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). It ...encompasses 154 deg^2 of deep, optical, high-quality, sub-arcsecond imaging data in the five optical filters u^*g'r'i'z'. The article presents our data processing of the complete CFHTLenS data set. We were able to obtain a data set with very good image quality and high-quality astrometric and photometric calibration. Our external astrometric accuracy is between 60-70 mas with respect to SDSS data and the internal alignment in all filters is around 30 mas. Our average photometric calibration shows a dispersion on the order of 0.01 to 0.03 mag for g'r'i'z' and about 0.04 mag for u^* with respect to SDSS sources down to i <= 21. In the spirit of the CFHTLS all our data products are released to the astronomical community via the Canadian Astronomy Data Centre. We give a description and how-to manuals of the public products which include image pixel data, source catalogues with photometric redshift estimates and all relevant quantities to perform weak lensing studies.
Objectives
To determine whether the Charlson Comorbidity Index (CCI) predicts short‐ and long‐term mortality.
Design
Prospective cohort study.
Setting
The medical department of two university ...hospitals and one community‐based hospital.
Participants
Acutely hospitalized individuals aged 65 and older with a mean age of 77.8 ± 7.9, 45.8% male (n = 1,313).
Measurements
In eligible persons, information on demographic characteristics, activities of daily living (modified Katz ADL Index score), and disease‐related measures was collected within 48 hours after admission. Follow‐up using self‐reporting questionnaires was performed at 3 months and 1 year. Functional decline was defined as a decline of at least 1 point on the modified Katz ADL Index score at 12 months from baseline. Mortality data at 3 months and 1 and 5 years were collected from the municipal database.
Results
Logistic regression analysis, adjusted for age and sex, showed that participants with a CCI of 5 or more had higher 3‐month (odds ratio (OR) = 3.6, 95% confidence interval (CI) = 2.1–6.4), 1‐year (OR = 7.1, 95% CI = 4.2–11.9), and 5‐year (OR = 52.4, 95% CI = 13.3–206.4) mortality than those with a CCI of 0. Participants with CCI scores between 1 and 4 also had greater mortality risk at 3 months and 1 and 5 years.
Conclusion
The CCI independently predicts short‐ and long‐term mortality in acutely ill hospitalized elderly adults.
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